1. Field of the Invention
This invention relates to a computer system of which remote operation is enabled. For example, it relates to a computer system suitable for remotely operating a desk-top multimedia computer from a portable terminal by means of communication.
2. Related Background Art
Recent popularization of office automation has rapidly broadened the use of computers in business environments, where various application software such as word processing and data base has been used for improvement of paperwork efficiency not only at offices but also on business trips or at user's destinations.
For such uses, portable personal computers having high level functions, generally called notebook or sub-notebook computers, have been used in the conventional cases. Since the same application software as installed in desk-top personal computers for offices is installed in such portable personal computers, the user can do his paperwork on a business trip or at his destination in the same manner as he do at his office.
When the consistency of data is required between the desk-top office computer and the portable personal computer used at user's destination, the data is usually copied from one computer to another through a portable recording medium such as a floppy disk or magneto-optical disk.
On the other hand, in advanced offices where each personal computer is connected to a server through a LAN, the user can use the portable personal computer at his destination to access to the in-house server through communication software, such as called remote office or the like, for downloading desired data. The data can thus be shared between the in-house server and the portable personal computer to secure the consistency of the data.
Recent tendencies to allow high level functions of such application software and develop graphic interfaces of OSs, however, require notebook or sub-notebook type portable personal computers supporting them to increase in the capacity of their hard disks and semiconductor RAMs and improve performance of their CPUs. Since such requirements cause an increase in power consumption and hence an increase in the capacity of their batteries, the portability of the notebook or sub-notebook type personal computers are made much worse and each battery life becomes relatively shorter. Besides, it goes against the tendency to require the cost efficiency.
In the computer system where data is copied from one computer to another through a portable recording medium to secure the consistency of the data between both computers, a copy error or improper copying cycle may often occur. On the other hand, with the computer system where each personal computer is connected to an in-house server through an in-house LAN so that the user can directly access to the in-house server and share data with the server at his destination, it is difficult for small offices having one or a few personal computers at most to introduce such an improved system because too much expenses are required.